The present invention relates to rotary heat regenerative heat exchangers and, more specifically, to improved means for constructing and supporting modular heat exchange baskets in the rotor.
A rotary regenerative heat exchanger is employed to transfer heat from one hot gas stream, such as a flue gas stream, to another cold gas stream, such as combustion air. The rotor contains a mass of heat absorbent material which is first positioned in a passageway for the hot gas stream where heat is absorbed by the heat absorbent material. As the rotor turns, the heated absorbent material enters the passageway for the cold gas stream where the heat is transferred from the absorbent material to the cold gas stream.
In a typical rotary heat exchanger, such as a rotary regenerative air preheater, the cylindrical rotor is disposed on a vertical central rotor post and divided into a plurality of sector-shaped compartments by a plurality of radial partitions or diaphragms extending from the rotor post to the outer peripheral shell of the rotor. These sector-shaped compartments are loaded with modular heat exchange baskets which contain the mass of heat absorbent material commonly comprised of stacked plate-like elements.
The rotor is surrounded by a housing and the ends of the rotor are partially covered by sector plates located between the gas and air inlet and outlet ducts which divide the housing into flue gas and air sides. In order to improve the efficiency of operation, it is conventional to provide seals, which are referred to as radial seals, on the ends of the rotor such that the seals will come into proximity with the sector plates and minimize the flow of gases between the hot and cold sides at the ends of the rotor. These seals are normally attached to the edges of the diaphragms.
The conventional modular heat exchange baskets are loaded axially into the rotor from the top end (duct end) between the diaphragms and stay plates are located between radially adjacent baskets for support. There are normally multiple layers of baskets stacked on top of each other.
In another design, the rotor is constructed for the loading and removal of the baskets in a radial direction through the side of the rotor rather than axially through the duct end. The multiple layers of baskets are positioned and supported in each sector between the diaphragms by gratings fixed between diaphragms at each end of the rotor and between each of the layers of baskets.